Like many a thesis defense (4)
I believe the answer is:
oral
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">like many a thesis defense</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for oral that I've seen before include "Verbal" , "By word of mouth, like some exams" , "Kind of examination" , "Relating to speech" , "Ant; tourist (dial.)" .)